The packet technology is widely used in network communication. With the packet technology, various encoded information, such as voice, image, and data, is transmitted on a network. Due to the restriction on the transmitting capacity at the transmitting end, or during a specified delay period, a packet information frame does not arrive at the buffer of the receiving end, and thus information is lost. This is a common scenario for lost frame. Moreover, a frame may be lost due to network congestion or transmission loss on a packet switching network.
At present, different lost frame concealment technologies comply with diversified voice encoding standards and are used to compensate loss of voice quality due to lost frames. An algorithm for lost frame concealment is embedded in some voice decoders based on code excitation linear prediction.
The existing waveform encoding technology provides an algorithm for lost frame concealment. This algorithm, however, can be used for only 8 kHz sampling narrowband signals instead of broadband signals, and cannot meet the requirements for high-quality calls.